ST. LOUIS -- What the Busch Stadium sellout crowd hoped would be the coronation of a new franchise single-season saves leader turned into a mess that not only stung in the moment, but also augmented the stakes of the Cardinals' next series at hand.

With boos raining down from the stands, Trevor Rosenthal walked off the mound on Sunday not only without his 48th save, but also without recording an out. A two-run lead dissolved into an 8-4 loss that saw Rosenthal stung for a go-ahead grand slam before the Brewers landed their final punch with Khris Davis' three-run blast off Seth Maness.

A team that had been 86-0 when leading after eight innings now has a blemish. The Cards own a three-game division lead over the Pirates who they open a series with in Pittsburgh on Monday.

"I get it. He gets it," manager Mike Matheny said of the feisty fan reception Rosenthal received as he exited. "Do I think anybody in our dugout was doing that? The answer was no. He has been great, he really has. The thing is he has been very good and he'll continue to be very good. This was just one of those days where I think everybody sitting in those stands wanted it as badly as we did. And they watched it slipped away."

Rosenthal, who had taken his third loss just two days earlier, looked off from the get-go. He allowed a leadoff single before losing control of a changeup that hit Martin Maldonado in the head. A walk loaded the bases, and an 0-1 fastball down the middle to pinch-hitter Jason Rogers cleared them.

"Rogers did a good job of getting a good pitch to hit there, knowing I couldn't really pitch around him much," Rosenthal said. "It was similar to the pitch that Davis hit, too. Trying to go away and it ran over the plate more than I would have liked."

Rosenthal, who's 47-for-50 in save opportunities, entered this series having allowed just one long ball in 66 2/3 innings. But he allowed two -- both go-ahead shots in the ninth -- in as many appearances against Milwaukee.

Fatigue, Rosenthal said, played no role in his command issues. Matheny downplayed it as well, pointing out how deliberate the team has been in building in rest for its second-year closer. This was only the second appearance for Rosenthal since Sept. 21.

"I felt good," said Rosenthal, who hadn't blown a save since July 12. "It just seemed like I was trying to get in a groove and couldn't quite get there."

Matheny called for Maness to begin warming after Rosenthal hit Maldonado, and he then made his first mound visit after Rosenthal bounced the next pitch in the dirt. He stuck with him after the five-pitch walk to Nevin Ashley, believing Rosenthal gave the club the best chance to escape the trouble.

"I've seen him make course correction right in the middle of the inning," Matheny said. "He's done extremely well. We need some strikeouts right there. He's a guy that can get it done."